Pleomorphism of argyrophilic nucleolar organizer regions in oral submucous fibrosis and oral squamous cell carcinoma

Background: Argyrophilic nucleolar organizer regions (AgNORs) is demonstrated to be useful in diagnostic pathology, mainly to distinguish benign lesions from their malignant counterparts. We aimed to correlate AgNORs pleomorphism with the severity of lesion in oral submucous fibrosis (OSMF) and oral squamous cell carcinoma (OSCC) using a retrospective study on 45 archival tissues. Materials and Methods: Silver nitrate staining was performed on archival tissues consisting of 20 OSMF and 20 OSCC. Five biopsies from normal oral mucosa acted as a control. One hundred cells per slide were observed for AgNORs dots, which were classified as typical (spherical) and atypical (large, kidney-shaped and clustered). Results: A positive and significant correlation was found between increased atypical shapes and increasing grades of OSMF and OSCC. Conclusions: AgNORs pleomorphism can be a reliable criterion to assess disease severity and progression in OSMF and OSCC.